Unraveling the proteomic landscape of red-fleshed apples to identify regulators of anthocyanin accumulation

ABSTRACT: Anthocyanins are colorful plant pigments with antioxidant properties, and a diet rich in these flavonoids bears health benefits. Therefore, a strong anthocyanin accumulation in edible plant parts is of significant interest, and in Malus domestica, the domesticated apple, certain red-fleshed apple varieties exhibit this trait. Enhanced anthocyanin accumulation in the flesh of apple fruits is attributed to the hyperactivation of the MYB transcription factor MdMYB10, which act as a key regulators of anthocyanin biosynthesis by inducing the expression of multiple biosynthetic genes. While several studies have explored the underlying genetic mutations and resulting transcriptome changes, there is a lack of research on proteome alterations that cause the red-fleshed apple phenotype. To address this gap, a mass spectrometry-based proteomics approach was employed. Comparative proteomics identified differentially abundant proteins in young and mature fruits of the red-fleshed ‘Bay13645’ variety compared to the white-fleshed ‘Royal Gala’. Whereas several MYB transcription factors were enriched during early fruit development, they were no longer among the hyper-abundant proteins in ripe fruits of the red-fleshed genotype. In contrast, anthocyanin biosynthetic enzymes were enriched more strongly in ripe fruits of the red-fleshed cultivar, indicating developmental stage-specific differences in the control of the pigmentation process. The proteomic approach also identified novel regulatory factors and enzymes that may contribute to the red-fleshed apple phenotype, including a BAHD acyltransferase, Mal d proteins, and transcription factors of diverse families, and their potential relevance for the exhibition of this trait is discussed.

INSTRUMENT(S): Orbitrap Eclipse

ORGANISM(S): Malus Domestica

TISSUE(S): Fruit

SUBMITTER: Qussai Abbas  

LAB HEAD: Bernhard Kuster

PROVIDER: PXD062840 | Pride | 2025-06-06

REPOSITORIES: Pride